Integrated circuits are typically manufactured on semiconductor material. In the common case, the semiconductor material is in the form of silicon wafers. The integrated circuits are formed on the wafers by one or more processing steps that are well known to those skilled in the art.
In some high-temperature processes, the wafers cannot be exposed to the atmosphere before they have cooled to an appropriately low temperature level. Exemplary are gate formation processes whereby plural wafers are introduced into semiconductor processing furnaces operating at around 1,000 degrees centigrade, and reactants in gas phase injected into the furnace selectively oxidize the semiconductor material. Thereafter, the wafers must be allowed to cool to approximately 600 degrees centigrade before being removed from the furnace and exposed to the atmosphere. Another exemplary process is the annealing of a titanium layer to form titanium disilicide on semiconductor wafers, which requires cooling from about 800 degrees centigrade, the annealing temperature, to about 150 degrees centigrade, the temperature at and below which the titanium disilicide coated wafers can be exposed to the atmosphere for handling. While the wafers are cooling, the utilization of the furnace is interrupted for an undesireably lengthy period, sometimes amounting to whole work shifts, so that the heretofore known semiconductor diffusion furnaces, in all such cases, suffer substantial production interruption, and revenue reductions.